Spectroscopic Verification of Adsorbed Hydroxy Intermediates in the Bifunctional Mechanism of the Hydrogen Oxidation Reaction
| Autor: | Xiao-Ting Wang, Yao-Hui Wang, Yue-Jiao Zhang, Zhong-Qun Tian, Petar M. Radjenovic, Huajie Ze, Xia-Guang Zhang, Jian-Feng Li, Jin-Chao Dong |
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| Rok vydání: | 2021 |
| Předmět: |
Reaction mechanism
010405 organic chemistry Chemistry Alloy General Chemistry engineering.material Surface-enhanced Raman spectroscopy 010402 general chemistry Photochemistry Electrochemistry 01 natural sciences Catalysis 0104 chemical sciences chemistry.chemical_compound symbols.namesake Adsorption engineering symbols Bifunctional Raman spectroscopy |
| Zdroj: | Angewandte Chemie International Edition. 60:5708-5711 |
| ISSN: | 1521-3773 1433-7851 |
| DOI: | 10.1002/anie.202015571 |
| Popis: | Elucidating hydrogen oxidation reaction (HOR) mechanisms in alkaline conditions is vital for understanding and improving the efficiency of anion-exchange-membrane fuel cells. However, uncertainty remains around the alkaline HOR mechanism owing to a lack of direct in situ evidence of intermediates. In this study, in situ electrochemical surface-enhanced Raman spectroscopy (SERS) and DFT were used to study HOR processes on PtNi alloy and Pt surfaces, respectively. Spectroscopic evidence indicates that adsorbed hydroxy species (OHad ) were directly involved in HOR processes in alkaline conditions on the PtNi alloy surface. However, OHad species were not observed on the Pt surface during the HOR. We show that Ni doping promoted hydroxy adsorption on the platinum-alloy catalytic surface, improving the HOR activity. DFT calculations also suggest that the free energy was decreased by hydroxy adsorption. Consequently, tuning OH adsorption by designing bifunctional catalysts is an efficient method for promoting HOR activity. |
| Databáze: | OpenAIRE |
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